From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-yx1-f53.google.com (mail-yx1-f53.google.com [74.125.224.53]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 176D837C114 for ; Sun, 29 Mar 2026 15:10:52 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=74.125.224.53 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774797054; cv=none; b=FgJlDZ7O3wPkOuewpWs5OcFXSQ+vba9275dx4uWY1/ZkJfdj3AtOQ+OVL6NYs35lG+0SxrF0w+E2Ns7H1rcac2hubk5z0fGqsHP5Bu2+Ua38zo+Hzo8/xFF0HtLCLla4VgWcVIjViZDL301zE72wgmLyMJdmWsekF/LC0RpkafI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774797054; c=relaxed/simple; bh=LLr5cmf3SYYozYXM1xWVhMV/tB13W4sXrryaCkfDtAI=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NuLH5fooMa+22M/rHTHnyupZX3d9LknlfhwBQUx9Mies/ymmXGfeA5A36lQd0rpoU4DUgw6Mkp11W1xs7limXYTWhgA1r9ucXQQtgXod/HU2SjMrj6GpjSQNQDFfkyiqdbjHPsF11HbE3qUnQnU8N3QHHs9K4hPmV8baVRxUMQU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=QNGxhWFX; arc=none smtp.client-ip=74.125.224.53 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="QNGxhWFX" Received: by mail-yx1-f53.google.com with SMTP id 956f58d0204a3-65015facf32so715193d50.1 for ; Sun, 29 Mar 2026 08:10:52 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20251104; t=1774797052; x=1775401852; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=LLr5cmf3SYYozYXM1xWVhMV/tB13W4sXrryaCkfDtAI=; b=QNGxhWFXskETE6GLekQJYDfjGzsz6l5JxFNH1lf/RPQLeCcr7b/MKxwbDhl7cLqm36 d28NVsjRWWY80+uh5FMFbAjIvwklcO+WTOkyI3A2eKjv98AH/jWpVoZH6d2v65ozNOIq ajYnnHfdglnl3GUW0sLiRJK+fBwnQocfwC3HajhXdJFuGSzPKbXgla7LkGiahr+qmIwK DsYw89F/nzt2POCfKCdlGZtcSqOxtpbDwIii/klccS8sDsU6ve2H6LNSRjnJhlEogfQS /FJjdVi9Y32e+k6TPS44cJfy9wYDvurYNuGcyD72EonW6YvelN6zV8rUviTE4orRDjUp XWGw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1774797052; x=1775401852; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-gg:x-gm-message-state:from:to:cc:subject:date:message-id :reply-to; bh=LLr5cmf3SYYozYXM1xWVhMV/tB13W4sXrryaCkfDtAI=; b=W/DPLxi1T5csNakdd2pJbP7LAz3kcgsPBth7Q/crdAzZ8fwGt50xBD7ScgsFeng3M1 SY91z9vKS7DsSHeDSJNqford1RkT4xtPJkVj/lGV/qNrTV+cuoR0XRfmTMBsYpVKPObh pSI8mM+dN4D/i9Kz0S52/fa7MQilBbqvdKcXROvjCFiszME8kEu4UD0Wi/H9+sMkyZYk Sa0hxSZcp76EzRmwBy370PHuiPwa9GIqXxfArGwTNGMraU7euwMcT1JKab3UxqbRE6FP qcycGSTHxvVpil+9TY/ayIdIaBg2tTrybNxNYRROXLtFHCilUS8TtHLsZY13cS95c04V QsZg== X-Forwarded-Encrypted: i=1; AJvYcCVXjanX9XBLJH+TA7K9Pk19GIFh0Pyp2YN7A9CMrKFUfxxov7cVhkM39ac6PJrfsoQexfBXk18=@vger.kernel.org X-Gm-Message-State: AOJu0YxVHOE+G2zW+0EZRgHJ/6AGJz1RFxoVAKnw8cpLxhCadEFCJ52G 1jMmfsFqLEWjlRT6jFc3oRWU/yEgdPc2ShlTw06vktUMg7qWbrs9WBi0 X-Gm-Gg: ATEYQzwnGn6ZWrRuBlKfEPwvo7Uu24ely/HtClQXJyZg/fLoFop8LNoOmjxCGYKSwlg 20/5wBYzEt3Gpt+1WmBC3/sH61t8IUM9A4FMXclAvq/hUK0jjTwvXWw5rs+na75fo5YxOLdMLTd H1SWcW+sZ5SWuum1Sur93OnKae/wvqWOJ1CJj1eBAspDT/ivfaerQduEr5KR7aEMw8c4R+3as9a iNHpyW4JUhpYZVOckPfSf8ExfwKzeLCnjPvApyQk7IKOqAYvG1d731MCaQPKDUFOTnymzL1sVES oX3GZGtMphrI92dyJhfNqSoHcved1g+3//bKIIGxz+BIj+PxoEd0oAa83ZJQR9YqFEk3Bni6WqC Xb0obXzI4tk8Mps/ixp6aE4fRKVAhxRJkZwEectoPiJhST6dmBJ0HRzbENuFiO8sIJqIZuz6Oeg YnSDMUsxHClV+ljOGMegj6buQIJk8TQ5um0V+CS5jU/wiVOWUWeA/phktChZ6TMQspoZTBYyovl q2QK3k2wPsBj3qrWn2bKOVMJMPLlcrRuLKOQj6welC2 X-Received: by 2002:a05:690e:14cf:b0:64e:e90c:5684 with SMTP id 956f58d0204a3-64ff742c558mr9453537d50.64.1774797052021; Sun, 29 Mar 2026 08:10:52 -0700 (PDT) Received: from [192.168.5.93] (76-224-22-216.lightspeed.sntcca.sbcglobal.net. [76.224.22.216]) by smtp.gmail.com with ESMTPSA id 956f58d0204a3-65009262fa2sm2601166d50.8.2026.03.29.08.10.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 29 Mar 2026 08:10:51 -0700 (PDT) Message-ID: Date: Sun, 29 Mar 2026 08:10:49 -0700 Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH net 0/2] Fix page fragment handling when PAGE_SIZE > 4K To: Jakub Kicinski Cc: "David S . Miller" , Alexander Duyck , Eric Dumazet , Paolo Abeni , Andrew Lunn , Simon Horman , Mike Marciniszyn , Lee Trager , Jacob Keller , Mohsin Bashir , Mina Almasry , netdev@vger.kernel.org, kernel-team@meta.com References: <20260324195123.3486219-1-dimitri.daskalakis1@gmail.com> <20260327202958.53d26d46@kernel.org> Content-Language: en-US From: Dimitri Daskalakis In-Reply-To: <20260327202958.53d26d46@kernel.org> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/27/26 8:29 PM, Jakub Kicinski wrote: > On Tue, 24 Mar 2026 12:51:21 -0700 Dimitri Daskalakis wrote: >> FBNIC operates on fixed size descriptors (4K). When the OS supports pages >> larger than 4K, we fragment the page across multiple descriptors. >> >> While performance testing, I found several issues with our page fragment >> handling, resulting in low throughput and potential RX stalls. > Google AI reviewer points out that we will also be toast if someone > configures the ring size to just 16 descriptors. Can you check what > is the min size that doesn't wedge w/ 64kB pages and let's just set > the min to that instead of the current 16? Yeah, this looks legit. Bumping the min to 32 should work, but I'll test/verify before submitting the fix.